Saw mill log carriage machinery



Dec. l5, 1931. E H, PERCY" k 1,836,496

sAw MILL LOG CARR'MGE MACHINERY 'l Original Fled\3an. 3, 1924 6 Sheets-Sheet l De. 1s, 1931. E- H; PERCY 1,836,496

1 SAW MILL LOG CARRIAGE MACHINERY origi11a1 Filed Jan. s, 1924 e sneeps-sneei 2.

samurai/1Q) [i e a Tomi 006s Haro/z Dec. l5, 1931. E. H. PERCY I SAW MILL LOG CARRIAGE MACHINERY Original Filed Jan. 5 1924 6 Sheets-Sheet 3 muq Dec. 15, 1931. E. H. PERcY 1,836,496

SAW MILL LOG CARRIAGE MACHI-NERY Original Filed Jan. 5, 1924 6 Sheets-Sheet 4 EDWIN H. PERCK Dec. 15, 1931.

E. H. PERCY SAW MILL LOG CARRIAGE MACHINERY original Filed Jan. s, 1924 6 Sheets-Sheet 5 Dec. 15, 1931. E, H. PERCY SAW MILL LOG CARRIAGE MACHINERY 6 Sheets-Sheet 6 Original Filed Jan. 5, 1 924 Patented Dec. 15, 1931 Um'ran i sra'rns MTENT ol-r-icrzv EDWIN H. nacion rom: nance,camronnraassrenon, :BY Masai-E ASSIGNMENTS,

merlin rnnscofrr COMPANY, Acoaronerion or Miei-,risen SAW MILL Loef` GAB-RIAG-EMACHINERY Application led'January 3, 1924; Serial No. 684,105. Renewed August 16, 1928.

This invention relates to saw mill machin-- ery' and particularly pert'ainst'o the means employed for clogging a log and aligning it on` the carriage with respect to the line of' out of'the saw.

Prior tomy invention it was proposed to equip saw mill carriages with pneumatically operated dogging devices and to provide a. centralized' control for such devices located convenient tothe carriage operators station adjacent the setting mechanism on the-carriage; the object being to expedite the dogging operations and to reduce'the number of attendants on a.- carriage to a minimum.

In carrying out this proposed arrangement it was necessary to install a telescopic pipe beneath the platform of the carriage to serve as means of communication between the air storage tanks andthe air cylinders by which the clogging devices were operated. Alsoit was necessary to arrange a network of valve controlled piping and air hose between the clogging devices and the point of control to accomplish the centralized con* trol idea.

The arrangement just outlined has not proven entirely practical from the viewpoint of elliciency and economy for various reasons, chief among which are, the very expensive equipment necessary to create and maintain suiiicient air pressure with which to op,- erate the various devices; the excessive amount of power required to operate the equipment; and the low degree of efficiency due to the impossibility of maintaining ythe piping, its control valves and the air cylinders leak-proof.

With the object in view of overcoming the disadvantages and shortcomings of the ari rangement just described and other prior methods, the present invention embodies the use of improved electrically driven dogging devices and a centralized electrical control therefor.

In carrying out this object I provide a battery of eficient dogging devices which are mounted on the usual knees on the 'head blocks ofthe log carriage. The dogging devices are equipped with electric driving' motors, the operation of which is controlled from a central point whereby the operator y i of' setting mechanism may exercisecomplete control over them at any time.

The battery of-dogging devices includes what I prefer to term a hook dog.l This device, under my method, is operated when a log is placed onthe carriageto grip the same and dra-w it tightly against the head blocks and knees and hold;l it in this position while one side ofthe log is being sawed flat. The hook dogi is so designed that when engaged with a log-it'will absolutely prevent endwise movement of the log during `the sudden changes in direct-ion of'motion of carriage, and it vwill also prevent the log from rolling into the saw during the operationl oi' the carriage. Y

The remainder-"oi1 the battery of machines is composed of what I prefer to term tong dogs. These dogs a-re also mounted-upon the usual knee frames and equipped with electricdriving motors. I

The tong dogs are operative to engage the top and bottom of a log or timber on the carriage in a manner which will not mar what `is termed the back-board. The tong dogs are employed to grip andfirmly hold a log in one position on the headblocks and `against the knees after one side of the log has been sawed flat and turned down on the headblocks.

No claim is made herein forl the tong dogs, these tong dogs being disclosed and claimed in my pending application for power operated clogging mechanism, tiled November 20, 1924, Serial No. 750,968.

- Further, I also equip certain of the knees with very `sim-ple and eiiicient tapering devices which are electrically operated. These devices permit a tapering log to be quickly aligned with respect to the line of cut of the saw, Also they permit the cutting of timbers to anyl desired `degree of taper.

As: before stated all of my improved equipment is electrically driven and the controls for the same are arranged convenient to the station ot the operator so that he may place in or out of operation any one or group of devices at his option. Y

By the use 'of my improved dogging devarious mechanisms.

vices and the electric drive and control therefor, I am enabled to greatly reduce the operating cost of a log carriage, as but a small amount of power is required and one operator may efficiently control and operate the Also, the initial cost of installation of my equipment is very low as compared with prior arrangements. Y,

One form which the present invention may assume is exempliiied in the following description and illustrated by way of example in the accompanying drawings, in which Fig. 1 is a diagrammatic view in plan of a saw mill log carriage, disclosing my-improved apparatus mounted thereon.

Fig. 2 is a diagrammatic view of the elec'- trical equipment of my apparatus and showing the controls therefor.

Fig. 3 is a perspective view of one unit of my improved apparatus and is what I hereinafter term a hook dog.

' Fig. 4 is aI side elevation of the unit disclosed in the preceding figure and showing the operating arms thereof in various positions.

Fig. 5 is a perspective view of another unit of my improved apparatus which is hereinafter termed tong dog.`

Fig. 6 is a side elevation of the unit disclosed in the preceding ligure disclosing its construction.

Fig. 7 is a. fragmentary View of the tong dog showing the. operating arm thereof in position engaging a log.

Fig. 8 is an enlarged View of the tapering mechanism and disclosing its connection with the setting rack of one of the knee frames.

Fig. 9 shows a detail view of a solenoid brake-releasing device employed in' connection with the motors.

' Referring more particularly to the accom.- panying drawings, 10 indicates a saw mill logl carriage of usual construction. In the presentY instance this carriage is shown as equipped with a running gear comprising a plurality of transverse axles 11 which are journeled in suitable bearings 12 fixed on the longitudinal sills 14e of the carriage 10. The ends of these axles are Vfitted with wheels 15 which are adapted to run on rails arranged in parallelism with the path the carriage is intended to travel. The carriage may be driven by any suitable form of driving mechanism, but as this forms no part of the present invention, it is not shown.

The log carriage 10 equipped with a plurality of head blocks 16 which, as in usual practice, are rigidly fixed transversely of the carriage in parallelism and at spaced distances apart. Although in this instance only four head blocks are shown, it is to be understood that any number may be employed as the number and spacing of the head blocks depends entirely upon the length of the carriage and the character and size of the logs to be sawed.

The head blocks 16 are formed with parallel guide rails 17 upon which the knee frames 18 of dogging7 devices indicated at A, B, C, and D in Fig. 1, are supported and guided for movement transversely of the log carriage. The knee frames 18 of all these devices are alike inconstruction and are formed at one end with a vertical aligning face 20. ln practice the faces 20 of the knees 18 cooperate with the surfaces of the head blocks to permit a log to be properly aligned with respect to a saw (not shown)v with which the carriage is intended to co-act. As stated, the knees 18 are guided on the head blocks for movement transversely of the carriage so that they may be operated to advance or retract a log with respect to the line of cut of the saw. For accomplishing this a setting sha-ft 21 is arranged longitudinally of the carriage beneath the head blocks. This shaft is fitted with pinions 22 which are in constant mesh with racks 23 fitted at the bottoms of the knee frames 18. The setting shaft 21 is operated by a set works 24 conventionally illustrated in Fig. 1. This set works is operated by any suitable power such as belt or electric motor. This set works is reversible and when placed in operation will, through the mediuni of the Vsetting shaft and the pinions thereon, advance or retract the knees with respect to the line of cut of the saw.v

H0070 (Zof/ The clogging device indicated at C in F ig. 1 is what I prefer to term a hook dog. ln practice this device is actuated when a logis first placed on the carriage to grip the top of the log and hold it tightly against the headblocks and knees While the carriage is operated to run the log through the mill until one side of the log is sawed flat. The log is then turned to place the flat side against the headblocks.

Reference being hadto Figs. 3 and 4 where the hook dogis most clearly illustrated, it will be seen that this device includes a base 26 which is mounted on the knee frame hetween upstanding lugs 27. The ends of the base 26 are itted with adjusting screws 27l which permit the base to be adjusted toward and. away from-the aligning face 20 of the knee while the base may then be clamped by means of cap screws 28 which extend through slots in the base and are threaded into the knee 18.

Bearings 29 are formed at the sides of the base approximately centrally thereof and serve as journals for a short shaft 3 fr subframe 32 is positioned above the base and is formed with a downwardly projecting bearing 33 which is pivoted on the short shaft 30 for a very limited amount of vertical swinging movement. The upward swinging of the subframe is limited by ay chain 34 which conmeets the front end of the subframe tothe knee. Downward movement of the member 32 is resisted by a comparatively heavy compression spring 35Y which is interposed between the underface of the subfraime and the bs'se 26.

The subframe 32 carries a reversible electric driving motor 36, the shaft of which is fitted with a pinion 37.` This pinion is in constant mesh with a gear 38 which is fixed on ay shaft 39 journaled in bearings 40 on the subframe. l

The movable vend of the subtram'e 32 is bi1 furcated to accommodate a pinion 41 which is fixed on the shaft 39, and an operating gear 42 with which the pinion 41 is in constant mesh.

The operating gear 42 is litted with a radia-ily extending crank arm 43. The inner end of a dog;r arm 44 pivotally connects to the outer end of the crank arm 43 by means of a friction joint 42a. The outer end of the dog arm is slightly arcuate and is fitted with a downwardly projecting spike 45 which is adapted to be engaged with the top of a log positioned on the head blocks.

To limit the swinging movement of the dog arm 44 with respect to the crank arm 43,

I form the inner end of the dog arm with lugs 46 and 47 which extend from opposite Sides of the arm and are engageable with the peripheral face of the operating `gear 42.

The dog arm 44 is guided' between a pair of rigid guide members 48' which are securely bolted to opposite sides of the knee 18. A resilient pad 49 is secured between the members 48 at the upper ends ythereo't to serve as a bumper for the arm 44.

The `motor 36 is equipped with brake 50. This brake includes a pair of brake shoes 51 which are normally held in rictional contact with-a brake drum 52 fixed on the motor shaft. The lower ends of the brake shoes are pvoted to the subfram'e, the upper ends are `loosely connected by a' rod 53 which is fitted with a spring 54 for normally holding the shoes in Contact with the drum. The brake shoes are automatically disengaged from the drum when the motor is started by a solenoid actuated brake releasing device such as is illustrated in Fig; 9. The solenoid is automatically energized when the motor circuit is closed and causes the brake releasing. device 55 to release the brake shoes 'from engagement with the drum. i Y f In operation, when the motor Ad6 is started, the operating gear 42 is caused to revolve, thus downwardly swinging the crank arm 43 and the dog arm 44 until the spike on the operating rod engages the log. kThe cra-nk arm continues to swing and when the lug 47 on the operating arm abuts against the gear 42, acts to draw the dog arm downwardly to 05 force the spike int-o the top of the log and pull the'log tightly againsti the hea/d blocks and .knees` The motor circuit is then opened and the brake grips the drum on` the motor shaft to prevent the latter -from turning. This holds the-dog arm stationary and prevents the log from rolling'.

In operation, when the motor 36 is started, the gear 42 is given a partial turn carrying Ithe crank arm 43 vand dog arm 44 downwardly until the spike on the dog arm strikes the and the crank arm continues to swing until the lug 47 on the arm 44 abuts 4against the gear 42, as shown in dotted lines, Fig. 4.

This acts to draw the dog arms downwardly the motor through a reversing switch presentlyto be described is operated in the opposite direction', causing the gear 42 to be turned to the right as viewed in Fig. 4.- The vcrank arm will lirst tend to thrust the dog arm upwardly, thereby removing the spike from the log, and when the'dog arm has been raised to a position where it strikes the buffer 49, it will be straightened out with respect to the crank arm, and the lug 46 will strike the base of the gear 42, thus stopping further movement o-f the' gear and stalling the motor.Y i

The hook dog just described is particularly eiiicient when used 12o-dog7 extremely large logs and l'ogs with heavy bark. device is intended to grip and hold the logon the head blocks until one side of the log has been sawed flat. The dog is then released and the log isturned to dispose the fiat side thereof onlthe surfaces of the' head blocks.

l/Vhen this has been done the ton-g dogs A, B and D are brought into operation to hold the log against the knee blocks until it has been sawed up. n

u Tong' dogs rThe tong dogs are identical in construction and operation.v Reference being had to Figs. 5, 6 and 7 where one tong dog is clear- -ly illustrated, it is seen that the device includes a base 55. This member is bolted to the knee 18 between upstanding lugs 56. A trunnic-n 57 projects from each side of the base and constitute pivotal connections between the l-'o-wer Vends vof vertical links 58' and 4the base. The upper ends of the links are pivotally connected to the rear end of an upper dog arm 59 which is fitted at its forward end with a downwardly curved hook pointl 60; The arm 59 carries' a reversible The oper- The , V5 log. The dog arm thereupon comes to al stop .trunnions 57.

'electric driving motor 61, the shaft of which is fitted with a pinion 62. This pinion is in constant mesh with a gear 63 which is fixed on a shaft 64. A pinion 65 is also fixed on Jthis shaft and is in constant mesh with a vertically disposed rack 66 which is pivoted at its lower end on a lower dog arm 67. The rack is held in mesh with the pinion by means of guide rollers 68 which are carried between a pair of plates 69 which are pivoted on the shaft 64.

rIhe lower dog arm is formed with a slotted rear end which is mounted on one of the rl`he forward end of the arm is fitted with an upwardly curved hook point 70. Y

At their forward ends, both of the Ydog arms are fitted with projecting studs 71 which engage a guideway 72 formed in a guide member 78. rlhis member is rigidly secured to the knee and is fitted at its upper end with a coil spring bumper 74 for cush` ioning the upstroke of the upper arm.

To actuate the dog arms to grip a log, the motor 6l is started. 4This motor, through the pinion 62 and gear 53 revolves the pinion G5 and causes the latter to travel down the rack 66 until the hook point 60 engages a log. The pinion will then cause the rack to travel up `wardly until the hook point engages the log. TWhen both the hook points have gripped the log, the circuit of the motor 6l is opened. rThe shaft of this motor is fitted with a brake drum for cooperation with a spring tension brake 75, which, when the current to the motor is shut off, will resist rotation of the motor shaft and thereby hold the dog arms in position. By reversing the motor 6l the hook points on the dog arms may be disen gaged from the log and returned to normal position.

Tapewng devices l/Vhen a tapered log is to be s'awed, it is essential that the small end be positioned to approximately line up the longitudinal cen ter of the log substantially parallel with the line of cut of the saw. To accomplish this, I have provided means, here termed the tapering devices, for shifting the knees carrying the tong dog7 devices transversely of the carriage independently of each other and of the set works.

Each of the knees carrying the tong dogs is fitted with a tapering device such as generally indicated at 75 in Fig. 6, but most clean ly shown in Fig. 8. This device comprises a screw feed shaft 7 6 which is journalled at its ends in bearings 77 on t-he base 55. At its rear end this feed shaft is fitted with a gear 7S which is in constant mesh with a pinion 79 fixed on the shaft of a reversible electric motor 80. This motor is supported by the base plate and is equipped with a spring tension brake 81. The gear78 is held into drivscribed between the gear 78 and the feed shaft is sufficient to cause the gear to revolve the shaft, but should the shaft become locked against turning movement, the gear will rotate free of the shaft.

A feedl nut is threaded on the feed shaft `and is formed with a downwardly extending arm 86. A substantially horizontally disposed link 87 connects this arm with the setting rack 23 which is slidably mounted in the bottom of the knee frame. when the rack is held stationary by the setting pinion 22 on the sett-ing shaft 21, and the motor 8O is started, the feed shaft will advance through the feed nut and consequently advance the knee lframe and dogging mechanism transversely of the carriage frame independent of the rack 23.

When the knee frame is to be returned to normal 'position in alignment with the other knees, the direction of operation of the motor is reversed to retract the feed screw through the feed nut until the end of the latter abuts against one of the stationary stops 011 the base. The screw feed shaft is then locked against rotation and the gear 78 will rotate larly desirable when 'sawing timber into tapered telephone and like poleswhere specifications frequently call for odd dimensions.

The hook dog, the tong dogs, and the tapering devices,`as described, are all electricaliydriven and may all be controlled from a central point convenient to the operator of the log carriage.

Each dog and tapering device has an individual motor which is of the reversible type.

The usual carriage will require but one hook Y dog. It is controlled separately from the tong dogs by its own switch, which, as here shown, is in the form of a foot-operated reversing switch located conveniently to the setworks operator. Should it bedesired-for anyA reason to use more than one hook dog on a carriage the additional one may conveniently be controlled by one and the same switch. The tong dogs, of which there are usually a plurality on a carriage, are all controlled by a single switch, which likewise is here shown in the form of a foot-operated reversing switch located conveniently to the set-works operator. If desired, an individual cut-out lswitch may be employed for each motor cir It is obvious that cuit operating :the-tong dogs, in case it should be desired to stop :the operationot one .pair of tong dogs Without interfering with the operation of the others. Each tapering de vice motor has .a eutout switch located .c011- Venntfly to the operator, and Iall .of the .tapering device motors are 4undercontrol of asin* gle reversing switch, as in lthe case of A.the tong dogs motors.

The control is diagrammatically Ashoyvn inv Fig. 2 where the letter E indicates thedriving motor of the Vset Works, should .it be driven this Way, the letter F indicates the motor of the'ifhook dog device, and the let.- ter H indicates the driving motors of fthe tong flogging devices. The motors .of the tapering devices are .indicated at .J The source `of electrical .energy for .all of vthese motors is indicatedat iK. In practicathelog carriageis driven .by steam :or Cableandfthje source of supply for thedoggng and other motors may bederved fromatlclley orfothejr collector kdevice .or from the .same source Ves the sot .works motor.

The motor rE of the set Works when used ieconneoted by conductorsfto anon-revers ing switch-91 which tnrll iis connected to the source of electrical energy. llhesivitch 91 when the set works is driven Vby electric' motor is located .within ,convenient reach vof the loperatoids.seat ,on the carriage which -is indicated at 92 `in Fig. l.

The driving motor F `of fthe hookdog is connected .by conductors "9,3 to a reversing switch 94 `which .in turn liS.COIlneote-d to the source of electrical supply. The reversing switch is .preferably :located beneath the platformoffthecarriage andoperatively connected toa foot pedalktll-a shown in Fig. a .which is located on the carriage in position Where the set ,Workso erator `ma .Controltheon eration ofthefliook dog? rom :his sea-t; The motors H of the -tong dogs are ,each connected by pairs ofconductors 95 todouble polesingle throvvswitchesl. Theseswitches connect to a pair of main lead conductors 9,7:

which are .connected to areversing switch 98. This swtchis connected tofthe source of electrical energy. zThe, switches 96 .are pref erably located inl a cabinet .or :fuse 190x199 which is `placed adjacent y.the operators 4.seat

on thelog carriageaS Shownin Fig. V11. The reversing switch 98 is preferably located ibeneath `the. carriage platform andoperatvely connected to a foot ypedal Il() Whichis shown in Fig. l as located Within convenient greach ofthe set .works operator7sstation.

'It is obvious thatfbythe provision `of vthe double pole switches 96 anda single lmain reversing switch 98, `the operator may cuts out ,any one of the fto ng dogs by .simply opening the switch 96 in thecircnit of the .tong dogs which :he :Wishes to remain iin'- operative. lBy closing fthe `reversing switch 98 the circuits ofthe' Amotors in .which .the

syvitcliesQG are closed `vill be completed and the tong dogs operated thereby Ywill be placed in operation.

The motors J of the `tapering devices are each connected :by .pairs of conductors 4101 to .doable `,pole single throw Switches 102.

These switches vconnect to a pair of main lead conductors 102) which are connected to a reversing `svvitch 102% This switch is 4connected to the .source of electricalenergy. yThe switches :102 .are preferably located in the inse cabinet as indicated at 99. The reversing switch 102 .may be `located under the platform similar to switch 96 and operated byfa pedal 103.

In actnaloperation, when a log is delivered to .thecarriaga the operatorcloses the circuit of the driving motor ofthe hook clogwhioh acts to grip the :log .and draw it tightly against the head ,blocks and the knees. ."llhe operator may then operate the set .works to align the log .with respect .to the .line otcutpf thesaw. VlIhe carriage .is thenplacedLin oper.- ationnntil .the oneside of the :log is savved fiat. vThe hook dog"is,then released by re.- versing its motor and the log `turned to vdiss pose the ifi at side onthe head blocks. The operator maythen ,bring into voperation all of theltong dogs to ^grip the .top and Vbottom of the llog and hold it .against the knees. Should it'ube necessary to taper thelogitoeline i-tiup,.the necessary svvitchesmay beclosedto opera-te one or moi-enf the tapering devices to advance thel'sele-ctediknee tobring theglons gitildinal center of .the log `snbstantially ,in alignment with the line ofcnt ,of the saw. The, carriage .maythenbe placed in; operation until the dog 1is completely sawed 11p.

By reversing the operation ofthe .driving motors ofthe tongdogsby .means of the switch 98,:thedogsmaybe released from e11- gagement .Withlthe logandreturned to an inoperative position. VThe switches of ftheyarions tapering device motors may ,then ,be closedto .retnrinthe .advanced knees .back into alignment with :the others. By providing the pedals for voperating the reversing switches with :the -fhook ldog. .motors and tongdog motors, the operator is enabled to `exercise controloverthese devices atany time. Also, .the cut-ont switches .of the tong dogY motors are Within convenient reach ofthe operator that he maycut-.out any one, anygroup, or.all offthetong dogslat hisoption. Thetapering device motorszmay also be operated from the voperators seat so that .a log may -be li ned .up quickly and vvi-th ease.

`ylVhile I haveA shoivnthe .preferred :form .of my invention as nowyknotvn to mepl .wishzit understood that various Achanges maybe made in lits ,construction lWithout departing from :the invention as .detinedin fthe appended. claims.

Having thus'descrbed myvinvention, .what

I claim and desire to secure by Letters Patent is l. il clogging device for saw mill carriages con'iprising a knee frame adapted to be slid- `i ably mounted on a head block and having a l ing gear to swing said arm.

2. A clogging device for saw mill carriages comprising a knee frame adapted `to be slidably mounted on a head block and having a vertical aligning `face, an operating gear journaled on said frame and having a radially extending crank arm, a vertically swinging dog arm pivoted at one end to said crank arm and having means at the other end for engaging al log on saidhead block adjacent said aligning face, a high speed motor on said frame for actuating said operating gear to swing said arm, and lugs at the inner end of said arm engageable with the periphery 0f said operating gear for limiting the swinging movement of said dog arm with respect to the said crank arm whereby the arm will be drawn downwardly and inwardly with respect to said aligning face when the operatn ing gear is driven in one direction.

3. A clogging device for saw mill carriages comprising a knee frame adapted to be slidably mounted on ahead block and having a vertically aligning face at one end thereof, an operating gear j ournaled on said frame and having a radially'extending crank arm, a vertically swinging dog arm pivoted at one end to the said crank arm and having means at the other end thereof for engaging a log positioned on the head block adjacent said aligning face, a high speed motor carried by the frame and operatively connected to said operating gear for actuating said doo arm, and lugs formed at the inner end of said dog arm engageable with the peripheral surface of said operating gear for limiting the swinging movement of said dog arm with respect to the said crank arm whereby the arm will be drawn downwardly and inwardly with respect to said aligning face when the operating gear is driven in one direction, said motor being reversible.

4. In combination with a head block, a knee slidably mounted thereon, a setting mechanism for advancing or retracting said knee along said block, said setting mechanism including the driving shaft having a pinion thereon, a rack slidably mounted at the bottom of said knee and in constant engagement with said pinion, a screw shaft carried on the frame, a feed nut on said shaft connected with said rack and normally constituting a rigid connection between said knee frame and said rack whereby they will move in unison, and meansfor operating 'said screw shaft for advancing or retracting the feed nut therealong whereby to advance or retract the knee along the head block independently of the rack, said means including a drivin" motor supported by the knee, a pinion on the shaft of said motor engageable with the gear on said screw shaft, and a connection between said last named gear and said screw shaft whereby the gear will be free to turn onsaid shaft when the shaft is locked from rotation.

.5. The combination with a saw-mill car-l riage having the usual knee f set-works, of power means for individually adjusting each knee for'taperingv a log, comprisin a rotatable shaft on the knee, a member Xed with relation to a part set by the set-works mechanism and engaging the shaft so as to cause the latter to-move longitudinally when rotlltefd, and a reversible motor for driving said S a t.' Y Y 6. The combination with a saw-mill carriage having the usual knee set-works, of power means for individually adjusting each knee for tapering a log, comprising a rotatable shaft on the knee, a member fixed with relation to a part set by the set-works mechanism and engaging the shaft so as to cause the latter tovmove longitudinally when rotated, and a reversible motor for driving said shaft, arlid a slip connection between the motor and s aft.

7. The combination with a saw mill carriage having the usual knee set-works, of power-operated means for individually adjusting each knee for tapering a log, comprising a screw shaft, a feed nut thereon, a motor for driving the shaft, a pointer on the feed nut, exposed to the view of a central set-works operator, and an indicator plate fixed to the base of the knee and co-operating with said pointer.

8. In a saw mill carriage, a knee, a hook dog thereon comprising a single log engaging arm mounted to swing in a vertical plane, an oscillatory member on which the log engaging arm ispivotally mounted, means to limit the pivotal movement of the log engaging arm in either direction, and a high speed reversible motor and reduction gearing for driving said oscillatory member in either direction.

9. In a saw-mill carriage, a knee, a hook dog thereon comprising a single log engaging arm mounted to swing in a vertical plane, a high-speed reversible motor carried by the knee, a driving connection between the motor and log engaging arm to cause the latter to swing in either direction, said driving connection including a mounting for the log engaging arm whereby'the latter may turn on iao a pivot after it strikes a log, and means for limiting the pivotal movement.

10. A sawmill carriage having head blocks, knees slidably mounted on said head blocks, a set shaft common to all the knees, driven members geared to the set shaft, there being one driven member for each knee,adjustable connections between the driven members and the knees, an elect-ric motor mounted on'each knee and gearing between each electric motor and the adjustable connection of its knee, said gearing including a slip connection.

EDWIN H. PERCY. 

